Former FBI Director James Comey has agreed to testify in open session before the Senate Intelligence Committee about the bureau’s investigation into Russian influence in the 2016 U.S. presidential election, intensifying President Donald Trump’s political troubles.

The announcement came from committee Chairman Richard Burr, of North Carolina, and Vice Chairman Mark Warner, the Virginia Democrat.

Donald Trump’s troubles intensified Friday as he left for his first foreign trip as president, with news emerging that investigators are focusing on a current White House official as a person of interest in their probe of Russian influence on the election.

Trump’s plane had been in the air less than hour when the Washington Post reported that the investigation into Russian meddling in the 2016 election had identified a senior White House adviser close to the president as a significant person of interest. The Post didn’t name the official.

The probe is about to accelerate as investigators shift from work that has largely been hidden from the public to conducting interviews and asking for grand jury subpoenas, the Post reported, citing people familiar with the investigation.

Also, the New York Times reported Friday that Trump had told top Russian diplomats who visited the Oval Office last week that firing FBI Director James Comey relieved “great pressure” on him. The report, which cited a U.S. official who has seen a document summarizing the meeting, said Trump also told the Russians the FBI director “was crazy, a real nut job.”

Spicer’s statements

White House Press Secretary Sean Spicer, who was on Air Force One with Trump when both stories broke, issued written statements responding to them.

Spicer didn’t confirm or dispute the comments in the Times story on the meeting with Russian envoys. “By grandstanding and politicizing the investigation into Russia’s actions, James Comey created unnecessary pressure on our ability to engage and negotiate with Russia,” Spicer said.

He responded to the report that a White House official is a person of interest with one sentence: “As the President has stated before, a thorough investigation will confirm that there was no collusion between the campaign and any foreign entity.”

The Trump administration already was engulfed in crisis as the Justice Department appointed former FBI Director Robert Mueller as special counsel to lead the investigation into Russian election meddling and whether anyone close to Trump colluded in the effort.

On Thursday, a day after the special counsel was named, Trump wrote on Twitter that the inquiry “is the single greatest witch hunt of a politician in American history!”

Trump had ignited political firestorm the previous week when he fired Comey, who was running the investigation. After the firing, associates of Comey leaked a February memo the FBI director had written describing a conversation in which Trump asked him to drop an investigation into former White House national security adviser Michael Flynn’s dealings with Turkey and Russia. (Source: NBC News)